Self-trailing truck.



S. L LONG. SELF TRAILINQ TRUCK. APPLICATION FILED MAR. I0. 1917.

Patented De a. 17,1918. 6 4 SHEETS-SHEET I.

S. L.-LONG. SELF TRAILING TRUCK.

APPLICATION FILED MAR. 10. 1917.

Patented Dec. 17', 1918.

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APPLICATION FILED MAR. 10, 1917 1,288,432. 1 Patented Dec. 17, 1918.

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"m r I IIIII I-I I I 'Z Z III'II S. L. LONG.

SELF TRAILING TRUCK.

APPLICATION FILED'MARJU, 1917.

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Patented De0.17,1918.,

UNITED STATES PATENT orrroii.

SIDNEY L. LONG, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR TO A. W. BENSONMANUFACTURING COMPANY,- OF MINNEAPOLIS, MINNESOTA, A CORPORA- TIONMINNESOTA.

To all whom it may concern:

Be it known that I, SIDNEY L. LONG, a citizen of the United States,residing at Minneapolis, in the county of Hennepin and State ofMinnesota, have invented certain new and useful Improvements inSelf-Trailing Trucks; and I do hereby declare'the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to trailing trucks which, when connected in atrain, will follow the same track whether the travel be on a straightline or on a curve, or tortuous line of travel.

Various difierent types of trailing trucks have hitherto been provided.Some thereof have had four Wheels, but usually they have had threewheels, two thereof being large laterally spaced axially alined mainwheels and a centrally located caster wheel. The four-wheeled trucks arerelatively expensive and heavy and do not trail as well as thethree-wheeled trucks, and on the other hand, in the above notedthree-wheeledtrucks, the caster wheels, in soft ground, plow up theearth, make the trucks hard running, that is, the draft heavy, andmoreover, do not run in the same tracks as the main wheels, so that inrunning on 'rutformed roads, will not follow the ruts, but must run overthe relatively rough crown of the road. I

I have reduced the draft of a train of trailing trucks to a minimum,provided a train of trucksihat will trail each other perfectly and eventurn substantially square corners, and obtain other advantages, such asa reduction in cost of manufacture, by providing a train of two-wheeledtrucks with vieldingly centered draw -bars arranged not only to producethe proper trailing action,

but to keep the truck bodies properly alined.

A train of these improved trucks illustrating the preferred embodimentof my invention, is shown in the accompanying drawings. wherein likecharacters indicate likeparts throughout the several views.

Referring to the drawings; 7 Figure 1 is a side elevationshowing a trainof improved trucks;

Specification of Letters Patent.

SELF-TRAILING TRUCK.

Application filed March 10, 1917. Serial No. 153,871.

Fig. 2 is a plan view of one of the yielding drawbars, some parts beingsectioned on the line 22 of Fig. 3;

Fig. 3 is a vertical section on the line 33 of Fig. 4:, some parts beingshown in full and some parts being broken away;

Fig. 4 is a transverse section taken approximately on the line 44 ofFig. 2;

Fig. 5 is a plan view showing one of the trucks on a larger scale thanin Fig. 1, and showing alsO part of the drawbar and coupling of anothercar, some parts being sectioned on the line 55 of Fig. 1; Fig. 5 is adetail partly in. section and partly in side elevation showing twocoupled drawbars;

Fig. 6 is an end elevation of the truck shown in Fig. 5;

- Fig. 7 is a plan view with. some parts sectioned and some parts brokenaway, showing the truck frame and draft yoke of the truck;

Fig. 8 is, a section on the line 88 0 Fig. 7;

Fig. 9 is a side elevation of one of the trucks;

Fig. 10 is a view corresponding to Fig. 3, but illustrating modifiedconstruction; and

Figs. 11 and 12 are transverse sections taken on the line 1112 of Fig.10, but

illustratingdifferent positions of the draw bar.

Describing first the construction illustrated in Figs. 1 to 9,inclusive, each truck wise rigidly secured to hollow anchor heads 16. Inthis preferred arrangement, drawbar anchors 17 in the form. of disk-likehubs, are swiveled in the said heads 16, for rotary, or limited rotarymovements on axes that are longitudinally central of the truck. Extendedthrough angular openings in the anchor hubs 17 are short drawbars 18that are capable of vertical oscillatory movements, and preferably alsohave limited endinward as permitted by the'anchor pins 19,

wise movements in the said hnbs'f'the connections between the .samebeing conveniently madeby transverse anchorpins 19 secured to the saidhubs and extended through longitudinal slots 20 in said bars.

The inner endsof the drawbars 18 are connected to the inner endsotdiv'erging springs 21, the outerends of which are anchored to thetruck frames 13. These springs 13 exert a force normally pulling thedrawba-rs as far and furthermore, tend to hold the said drawbars in, orparallel to the plane of the. truck frame. The said drawbars are notpermitted much, if any, lateral oscillation.

In the construction illustrated in Figs. 1 to 8, inclus'ive,the drawbars18, at their outer ends, have forked heads 18, which,

when interlapped,-are adapted to be pivotally coupled together bycoupling bolts 22 (see particularly Figs. 1, 5 and 5 These draw-bolts,at their lower ends, have nuts 22 and at their upper ends are providedwith shoulders between which and the upper prong of the adjacent couplerhead 18, a

short coiled spring 22 is interposed. When this nut-equipped bolt istightened against the spring 22, the connected coupling bars of the twoconnected trucks will be capable of pivotal movement under,'however,considerable frictional resistance against movement. The amount of thisfriction may be varied, by variably tightening the nut on the bolt. andit serves to prevent undue lateral vibratory or pivotal movements of theconnected drawbars. This its important,

especially in running down hill.

it should be further stated that the two coupled drawbars, when coupled,whilecapable or lateral pivotal movements, will have little, if any,vertical movement, one in respect to the other. Moreover, it should benoted that the coupling pins 22- (see Figs. 1 and 5) are located midwaybetween the axes or the connected trucks. This is irnportant and is oneof the features that makes the two-wheeled trucks self-trailing intraveling tortuous paths or curved cor-'-' ners. Also, this arrangementmakes a train of connected trucks self-trailing when drawn in eitherdirection, to-wit, either forward or backward, the terms"forward andbackward being used for convenience only. The trucks may, of course,vary a grea deal in character, both as to size and design. in thedrawings, trucks suitable for carrying sand or gravel,-for example, areillustrated, and hence, are provided with bore like bottoms :23, whichwould have suitable drop bottoms, not shown, nor necessary for thepurposes of this case to consider.

in traveling a circle, for example, the coupling pins'22, which are thepivotal connections between the trucks, being midover rough roads thansmall wheels.

rat-lease way between the axles of the truck wheels,

will, as is evident, keep the axles pointed toward the center of the,circle being traveled, and hence, as is obvious, the corre-' spondingwheels of the several trucks must travel preciselythe same paths. Thesame Y principle applies when the train is travelingeither on a straightline, or in a tortuous line of travel.v In turning so-called squarecorners, the trucks do not, of course, make their turn at an abruptangle, but theviwill approach such angle so closely that the train oftruckswill very abruptly turn on '2. rectangular corner.

Tn traveling I a smooth road, the truck frames and the drawbars will, bythe springs. 21, be held horizontal and'inalineinent, but in traveling ahilly read, such as illustrated in Fig. 1, for example, the said springswill yield and permit the drawbars to assume angular positions whileholding the truckframes approximately- .ho'rizontal. The loads 'on thetrucks being balanced on the wheels, no great force is required tomaintain them in ahorizontal position or to restore them to horizontalposition, in case they be temporarily tilted. The swivel con nectionbetween the drawbars and the framesalso permits the truck wheels toadapt themselves to lateral irregularities in the roadand the springs 2ltend to restore the said I drawbars to their normal'rotary positions.Obviously, the above described'arrangement reduces the number of, whelsabso lutely required for a trainot trucks,; to a, minimum.' It also notonly 'permits,but, makes desirable, the use ot l arge wheels which, asit well know, will rum more eaiiy e large wheels, moreover, permit theload to be carried low down, and in many instances,

even below the axles'of the wheels, which latter construction reducesthe tendency of the trucksto tilt.

Trains of trailing trucks of the character above described are highlyserviceable'for numerous purposes. Not only are they well adapted foruse in hauling sazidand gravel,

In the modified construction. of the am 7 bar shown in Figs. 10, 11 and12', the said drawbar 18, at its intermediate portion, has upper andlower long tudinal grooves or depressions 2 2 that are engaged by therounded heads f spring pressed bolts 25 working through the top andbottom plates of the anchor heads. In this arrangement also, thedrawbars are permitted vertical osclllatory movements, limited endwisemovement, and

limited axial rotary movements.

Figs. 10 and 11 show the drawbar in normal or neutral position and Fig.12 shows Attached at one end to the ide end portions f the truck framesand having at their free ends, interlocking perforated couiling heads 27adapted to be connected by bolts or keys 28, as shown in Fig.

In Fig. (3, these chains, being out of use, their free. ends are shownas coupled to hanger hooks 29 on the sides of the truck box From theabove description, it will be understood that this invention relatesparticularly to trains of trailing trucks, made up of quite a largenumber of trucks, to-

wit, three or more. When one trailing truck is connected to anautomobile, for instance, there is no difficult problem in maintainingthe balance of a two-wheel trailer truck.

When, however, a large number of two- Wheel, trailing trucks areconnected, other and many difiiculties are encountered. In running onundulating roads, the one truck will necessarily frequently be lowerthan the two trucks to which it is connected, and this r quiresvertically yielding coupling devices. If these vertically yieldingcoupling devices are not made resilient that is, if spring elements ofsome form are not provided, which tend to keep the coupling devicesvertically in normal 'or intermediate positions-then the two-Wheeltrucks will topple over endwise, and an oscillatory lashing action in avertical direction will be set up which will make the trainuncontrollable.

Hence, it will be understood that both the vertically yielding action,and the springs, or a resilientmeans tending to keep the couplingdevices vertically in intermediatepositions,-are of the utmostimportance. The ver tically yielding action permits the truck to run onundulating roads and the springs, or resilientmeans, exerts sufiicientforce to keep the truck bodies in approximate balance on the respectivetruck wheels, and if at time the truck bodies are thrown slightly fromtrue balance on their wheels,

the springs will restore the same good balance in again running on levelroads.

In this way, the truck bodies are kept in approximate balance n theirwheels, that is, are prevented from rocking forward or rearward so as tothrow the center of gravity of the load very materially from thevertical line of the axis of the wheels.

\Vhat I claim is:

l. A train of connected two-wheeled trucks. said trucks, at oppositeends, having projecting drawbars connected to the respective truckbodies so as to steer the same, but capable of vertical angularmovements in respect to the truck bodies, and yieldingly held normallyin verticalintermediate positions, so as to thereby hold the tru'clcbodies in substantial balance on the truck wheels, aid drawbars,approximately midway between the wheel axes of the connected trucks,being pivo'tally connected by coupling devices that permit relativehorizontal angular movement of the pivotallv connected drawbars, toproduce the trailing action, but hold the said connected drawbars forcommon vertical angular moven'ients.

2. A train of connected two-wheel trucks, said trucks, at opposite ends,having vertically yielding draw-bars pivotally connected intermediate ofsaid trucks for com mon vertical angular movement, but having relativelypivotal lateral movement to produce the trailing action of the trucks,and springs yieldingly holding said draw-bars vertically in intermediatepositions, the vertical yielding action of said draw-bars permitting thetrucks to run on undulating roads, and said springs holding the truckbodies inapproximate balance on the re-. spective truck wheels.

3. A train of connected two-wheel trucks, said trucks, at opposite ends,having vertically yielding draw-bars, pivotally connected for commonvertical angular movement. but having relatively pivotal lateralmovement to produce the trailing action of the trucks, said draw-barsfurther being mounted for limited rotation on their longitudinal axis,and springs yieldingly holding jsaid draw-bars vertically and rotativelyin normal intermediate positions, the yielding actions of said draw-barspermitting the trucks to run on undulating roads, and said springsholding the truck bodies in approximate balance on the respective truckwheels.

at. A train of connected two-wheel. trucks, said trucks, at theiropposite ends, having vertically yielding draw-bars pivotally connectedintermediate of said trucks for common vertical angular movements, buthaving relatively pivotal lateral movement to produce the trailingaction of the trucks, said draw-bars further having limited axialmovement and limited rotary movement on 'rcrti the r drew-hers in normalpositions, the yiel olctions oi seiol' clreW-bars permittii g 1e truckstor'un ori undulating roads,

one. '3 springs holding the truck bodies ie'te'balence on the respective'i'JlTi C having two laterally vices approximately equitlistent from theUlffifiltl wheel's, said coupling-device's never e vertical yielniingaction and being resili 1 lielclnormally in vertically'in terznerpositions said coupling devices treiling truck, halving two leterallyspecefi'vtheelekerrying its entire load, e'ncl piovicletl with front andrear coupling '(levices approximately equidistant from '-the time ofsaid'wheels sei'cl coupling devices having a vertical yielding actionlan'cl bemg resiliei-itly held normally in vertically inter-- mediategositions, said coupling devices further having a resilient limitedrotary movement, and resilient llmitecl' ax al l movement,

7 ii truce L its axis one springsyielclingly holclliilg carrying itsentire load, aiicl' provided .Wlllli II'GIH, LI1C-.'1'&T coupling clerig: e resilient limited rotary rear "with swi'veleml anchor hubs,clr'ew hare hubs fox-limited vertical oscillatory movements in respectthereto and .for limiting rotary movements i3l1QI'6Wltl1,, andfor-111ml;-

ecl enclwise movements therethrough andv springs rielclingly drawingsaid drawbars inwe-rxi e' cl' normally holding the same vcrticallycentered, the seid'clrawbersat their 'imtermedilately' fulcr'umecl insaid' anchor axis of said Wheels, said coupling devices 'ha vingevertical yielding actionencl being resiliently held normally invertically inter- 'ni"ediatepositions, and 'edjusteble frictional meansapplied to said coupling devices and: yieldingly holding the sameagainst lateral pivotal movements.-

' In testimony whereof I afiix' signature presence of two Witnesses. 7

SIDNEY L. LC NG seer BERNICE l fireeimg

